Hoist control



June 12, E. B. LEAR ETAL y HoIsT cNTRoL Filed May 4, 194,2 2 Sheets-Sheet l J0 28 33 za :mam WEA ARL l. JAR BYJOH/V A. H0105 ATTORNY June 12, 194s. E, B, EAR ET -AL 2,378,225

HoIsT CONTRL Filed May 4, 1942 2 Sheets-Sheet 2 4INVENToRs 50 ARL EAR 45 84 s 43 V45' B-Y JOHN A. HOPE 47 44 if?. 7 I ATTORNEY- Patented June 12, 1945 Earl B. Lear, Garfield Hei Lakewood, Ohio, assig ghts, and John A. Hope, nors,

by mesne assignments, to The Cleveland PneumaticTool Company,-Cleveland, Ohio, a corporation of Ohio Application May 4, 1942, Serial No. 441,646

2 Claims.

This invention rel-ates to improvements in power hoists, and has reference particularly to hydraulic means for controlling the operation of the hoist, which means may be located at any convenient point either adjacent to or remote from the hoist adapted to cut oil' circulation between a reservoir and the housing and to connect the inow chamber of the housing with one only of a plurality of clutch operators. f

A further object of the invention is the Drovision of novel valve means for the purpose stated.

Other objects and features of novelty will appear as we proceed withv the ydescription of that embodiment of the invention which, -for the purposes of the present application, we have illustrated in the accompanying drawings, in which,

Fig. 1 is an elevational View of a power hoist embodying the invention. l

f Fig. 2 is an end view of the same looking in the direction of arrows 2 2 of Fig. 1.

Fig. 3 is a longitudinal sectional view on a larger scale taken substantially on the line 3 3 of Fig. 2, illustrating a reservoir and gear pump which may be employed in connection with the invention.

Figs. 4 and 5 are transverse sectional views taken substantially on the lines 4 4 land 5 5 of Fig. 3.

Fig. 6 is a detail sectional view taken substantially on the line 6 6 of Fig. 5.

Fig. 7 is a transverse sectional view on a larger scale, taken substantially on the line 1 1 of Fig. l. .y L

Figs. 8 and 9 are detail sectional viewstaken l substantially on the lines 8 8 and 9 9 of Fig. 7.

Fig. 10 is a sectional view on a larger scale taken substantially on the line lll-I0 of Fig. l showing the two control valves in neutral position.

Fig. ll is a view similar to Fig.10, butwith one oi' the control valves in actuated position, and

Figs. l2, 13V and- 14-are cross-sectional views taken substantially on the lines |2 2, |3 |3 and |4 |4 of Fig. 10.

In Fig. l of the drawings 20 indicates a pair of sledge runners or other supporting frame members upon which the different elements of a power hoist are mounted. As indicated herein these ele,- ments may comprise an electric motor 2|, a iiexible or yielding drive 22,a gear bo'x'23, a pair of drums v24 and 25, clutch means for each ydrum comprising clutch bands 26and 21, and brakes for the individual drums comprising brake bands 28 andv 29. The construction includes transverse frame members, 3| and 32 suitably attached to the sledge runners 20 and connected above the drums by a tie rod or brace 33. The parts thus far described are more or `less conventional. While two drums 24 and 25 are disclosed herein it will be obvious that in some aspects of the invention the'number of drums may be varied, 'that is a single drum or more than two drums may be used.

In the frame members 30, 3| and 32 there is journaled a shaft 35, as by .means of roller bear ings one only of which is shown at 34 in Fig. 3. This shaft is driven by a motor 2| through reduction gearing, not shown, in gearbox 23.

The clutch band 21 surrounds and is Iadapted to engage a cylindrical clutch surface on the periphery of a planetary gear carrier 36 that is rotatably mounted on shaft 35, as by means of roller bearings 31. A', similar construction isv provided for the other hoist drum 24 and for any additional drums when used. .When the carrier 36 is held against rotation by the contraction of lbami 21 drive is communicated from shaft 35 through a sun gear A keyed to the shaft and through planetary gears B 'mounted on the carrier 36 through idler rollers C, the gears B in turn mesh.- ing with an internal gear D ilxed with respect to the drum 25, this type of gear drive being well known in hoists.

Suitable means for contracting thev clutch band 21 is shown in Fig. 7, where shoes 38 are riveted l,

to the ends of the band and are fastened by bolts 39 or the like to shoe. gripping arms 40 which have bifurcated ends through which are pins 4| that project.through elongated lslots 42 in ears that are integral with pistons L|13, These pistons fit within cylinders that are formed invblocksr 45 which are fastened to the runners 20. y Each of these pistons may be provided with suitable packl ing 46v held in place by rings 41 and headed screws 46- Motivevfluid may be admitted to the cylindersv 414I behind theY pistonl heads through drilledV passagesl 49. Normally the pistons 43 are forced away from each other by a compression spring 50 which thereby functions additionally to` expand clutch band 21. i The frame member 32, as indicated in Fig. 3. has a central-opening large enough to receive an annular flange 5| madeintegral with a housingv 52 which is hollowed out to form a reservoir 53 which may be filled with oil or other suitable liquid through an opening in its upper side normally closed by a screw plug 5t. A port 55 connects the reservoir with a cylindrical valve socket 56, and a second port 51 connects this socket with a nipple 58 to which a discharge line 59 is connected. Housing 52 may besecured to frame member 32 by screws 9B or the like.

On the outer sideiof housing 52 there is mounted, as by means o screws 6|, the housing The hub of pump gear 53 has a dog clutch connection with a short shaft 59 mounted for rotation in a bushing 19 that is carried in housing 52. The opposite end of shaft E9 has a dog clutch connection with a `plug 'H that is mounted in the end or hollow shaft 3,5 and is held against rotation with respect thereto by a pin 12. The

gear pump is thereby coupled to drive shaft 35.

A cylindrical valve 13A is rotatably mounted in valve socket 56, vwhich valve is cut away to form passages 14 and 1,5, and is provided with a stem 13' extending through a retaining plug 16 threaded into the outer end of the valve socket 56. To the valve stem may be attacheda handle or the likel by means oi which the valve may be turned through an angle of 90, its motion being limited to `that amount by a pin and slot 11, 18 at its inner end. When this valve is in the position illustrated liquid from the reservoir flows through port 55, passages 'HL-'68 and 66 to the pump, through the pump, and then through passages 55, E1 and 15 to port 51. If, however, the direction f rotation of the pump gears should be changed, the valve 13 may be turned through an angle of' 90 from the position illustrated,

` whereupon the flow of liquid from the valve socket 56 through the pump and back tothatsccket will be reversed. y

In orderY to limit thepressure which may be set up by the pump in the ,discharge line 59 provide a icy-pass between port v51 and reservoir 53 in which is mounted .a valve that is adapted to yield when predetermined pressure is reached. Thisby-pass is marked Sii in the drawings. At an intermediate point ofitslength it is intercepted by a valve chamber 3| in which is `mounted a cylindrical valve piece S2 which is urged toward its seat by. a coil spring B3 that is backed by a screw 84 which may be turned vone-way or the other to Aadjust `the force of the spring. A screw cap 85 servesgto exclude dust and protect the valve. i l Y The control for the liquid circulated by the pump is located at some point convenienti-i0 the operator, and comprises a valve housing 86 which in the present instance is mounted by means of bolts 81 upon a bracket 83 carried by the brace rod 33. This valve housing 8B has -two cylindrical bores 89 and 90 which extend fromtop-to bottom of the housing. An iniiow chamber 9| and an outiiow chamber 92 intercept both of these bores. There are also annularv pockets S3 and 94 surrounding bore 89 between chambers 9| and 92 andsimilar pockets 95`and S5 surrounding bore 99. Pockets 93 and '96 are-connected -by a cross passage 91 and pockets 94'and 95 are connected Vby a similar `cross passage 98.- -Below lthere are constrictions |99 and H0.

the iniiow chamber 9| there are two annular pockets 99 and H10 surrounding the bores 89 and 9B respectively.

Two plungers and |02, which may be identical in form and size, are mounted to slide in bores 89 and 90. These plungers are urged upwardly by two coil springs mit and |04 backed by screw plugs iii-5 and 105. 'The upward movement of the plungers is limited by nuts |91 and |08 as illustrated in Fig. l0. In plunger 10| Constriction |99 serves to connect pocket 93 with chamber 92 when the plunger' is in its normal or neutral position. Constriction H3 connects chamber 9| with pocket 94 when the plunger is in neutral and with pocket 99 when the plunger is depressed, as illustrated in Fig. 1l. Similar constrictions I and H2 in plunger |02 function in like manner for connecting pocket 95 with chamber 92 and for connecting pocket 96 or pocket |09 with chamber 9|. Drilled passages ||3 and ||li extend-upwardly from the lower ends of the plungers and connect with ports ||5 and HG, respectively, the latter ports communicating with chamber. .f92 when the plungers are in their neutral or upper position.

Communicating with pockets 99 and |00 are two nipples Hl and H8 from which extend tubular conductors H9 and |29. Conductor H9 extends downwardly to the base of themachineand has branches which communicate with the 4passages |39 in the cylinder blocks t5 previously referred to. Conductor |29 extends down ysimilarly and has branches which run along the base of the ma chine to a second set of cylinder blocks identical in form and function with the blocks i5, in which operate pistons similar to the pistons litforthe actuation of clutch band 2B. f I

In the valve housing S5 there is a nipple |2I communicating with inflow chamber 9| to which tubular conductor 59 is connected.- Liquid from the delivery side oi the pump therefore flows into chamber iii. Nipple' |22 is mounted in the valve housing in communication; with the `outflow chamber 92, and with this nipple there is connected a tubular conducto-r 23 which extends downwardly to a nipple 124i mounted in the reservoir housing 52 near the top' of the latter. Hence liquid received in chamber 92 may ow back to the reservoir through conductor |23..

The plungers |9| and |92 could of 'course be arranged to be depressed directly by the opera-'- tor, but in order to reduce the necessary effort somewhat we prefer to provide a pair 4of levers and |26 with knobs |21 and |28 on their ends, which levers are pivotally Vmounted'in bifurcations in thev upper ends of plungers' |01 "and |02, the fulcrums of the levers being supported'. bylinks |29 that are pivotally mounted upon ears attached to the housing 86, as shown in Fig. 1. f A

Operation- Assuming that the motor. 2| '7 is running and that the shaft is turning accordingly and the gear pump operating, and assuming that the control valves are in the neutral positions illustrated in Fig. 1G, liquidwill then'y be circulating from the reservoir through port 55, passages 14,58 and. 66 to the pump', and from the pump through passages 6'? and 15 to the conductor 59, whence it willflow tothe inflow chamber 9| of the Valve housing S5. 'From'the cham# ber 9| it flows in parallel tothe chamber92, that is to say around restriction H9 into pocket 94, through cross passage 98- to pocket --95 'and through restriction to chamber i92, andtalso around "restriction H2 to pocket 98, through up in the cylinders because of the fact that free circulation at lowpressure is permitted from the pump through the valvesand backto the reservoir. A

Now if it is desired to operate hoist; drum 25 the operator depresses knob |21 and thereby moves plunger downwardly against the action of spring |03 to the position illustrated in Fig. 11. This cuts off both paths of flow from chamber 9| to chamber 92, since constriction |09 no longer connects pocket 93 with chamber 92 and constriction I0 no longer connects pocket 94 with chamber 9|. Both of the cross passages 91 and 98 are therefore blocked. Inflow chamber 9| is however connected with pocket 99'by constriction ||0 and a flow of liquid is set up from pocket 99 through tubular conductor ||9 to the passages 49 leading to the two cylinders 44. The pistons 43 then move toward each other against the action of spring 50 and the clutch bandy 21 is contracted upon the periphery of the planetary gear carrier 36, resulting in the rotation of drum 25. The passages ||3 and ||5 through the plunger are at this time cut olf from the pocket 99, as will be apparent from an inspection of Fig, 11.

When it is desired to unwind the hoist the operator merely releases knob |21, whereupon plunger A|0| returns to neutral position under the influence of its spring |03. When this occursboth cross passages 91 and 98 are again opened up and the normal low pressure circulation of the liquid resumes. At the'same time pocket 99 is put into communication with the passages ||3 and I|5 through the plunger and the pressure previously built up in the line ||9 is exhausted by way of the chamber 92 with the result that the spring 50 expandsand forces the pistons 43 apart and into their cylinders, thereby expanding the clutch band 21 and leaving the carrier 36 free to rotate idly.

When the drum 24 is to be operated a similar procedure is followed except that plunger |02 is manipula-ted instead of plunger |0|. The apparatus functions in the same-way to stop low pressure circulation throughboth of the cross passages 91 and 98 and to open up pocket |00 to the inflow chamber 9|, so that pressure fluid is transmitted through conductor to the operating cylinders for clutch band 26.

In cases where it is more convenient to reverse change by merely shifting valve 13 from the ,posithe position of the machine with respect to the work, making it necessary to reverse the direc! tion of rotation of shaft 35, whereby the direction of rotation of the pump is also reversed,

we can accommodate the present control to this tion illustrated to a position at right angles to that illustrated. The connections for the'pump While we have shown herein two cross paswill thenf be correct because' the intake for the pump will then flow from port through passage 15 to passage 61 and the discharge will flow through passages 68 and 14 todischarge port 51.

During actuation of a drum to perform a hoist- "ing operation valve 82 remains closed until pressure has been built up sufficiently to cause clutch band 21 tormly grip the periphery of planet gear carrier 3B. Thereafter valve 82 opens sufficiently to let the discharge from the pump flow through the by-pass back to the reservoir 53,

but not sufficiently to materially lessen the pressure in cylinders 44. f

sages 91 and 98 in the valve housing 86through which the 'flow of liquid in parallel from cham- -ber 9| to chamber 92 is permitted, and while We prefer this arrangement when the hoist embodies two drums, it will be apparent that a single passage between these chambers would be within the spirit of the invention since either one of the passages 91 or 98 may be blocked by the depression of either one of the plungers |0| and |02.

Having thus described our invention, we claim:

shaft comprising a clutch, and hydraulic operating means for said clutch, said operating means comprising a gear pump supported by but separable from said frame endwise of said shaft, and a shaft extension in said pump aligned with and driven by said shaft but separable therefrom, one of the gears of said pump being carried by said shaft extension.

2. In a power hoist, a frame, a drive shaft journaled therein, a drum rotatable around said shaft, means for rotating the drum from said shaft comprising a clutch, and hydraulic oper-y ating means for said clutch, said operating means comprising a reservoir attached to but separable from said frame, and a gear pump attached to but separable from said reservoir, a shaft extension in said reservoir aligned with and driven by said shaft but separable therefrom, a shaft extension in said pump aligned with and driven by said first named shaft extension but separable therefrom, one of the gears of said pump be'. ing carried by said second shaft extension EARL B. LEAR. JOHN A. HOPE. 

